The present invention relates to an ultrasonic range finder having a transmitting ultrasonic sensor and a receiving ultrasonic sensor, and, more particularly, a technique for suppressing the influence of direct transmission waves propagating from the transmitting ultrasonic sensor to the receiving ultrasonic sensor.
In addition, the present invention relates to an ultrasonic sensor, and, more particularly, to a technique for attenuating direct transmission waves propagating within a case by improving a holder structure of an ultrasonic vibrator.
Furthermore, the present invention relates to an ultrasonic vibrator, and, more particularly, to a material for fabricating an acoustic matching layer.